Telling students what they can or cannot eat with government given money = acceptable
Telling grown adults what they can or cannot purchase with government given money = not acceptable
Makes sense.
It's not government money, it's their money. Once it is dispensed to them, it is no longer the government's.
That said, I don't necessarily have a problem with setting some guidelines on how vouchers or quasi-money can be spent (e.g., food stamps), but if the assistance is in the form of $$ itself, then once the $$ transfers to the possession of beneficiary, it is their money, and they ought to be free to spend it how they please.
What I particularly abhorrent about the recent law in Kansas, and other conservative initiatives to dictate how public assistance can be spent, is that they are NOT motivated by prudent fiscal conservatism but by mean-spirited attacks on the poor, which are based in the worst kind of negative stereotypes (e.g., takers, welfare queens).
If, those pushing these laws had actual, good evidence that abuse of public assistance were systematic and rampant, then it's a different matter, but they don't. It's a solution to a non-existent problem, just like voter ID laws supported for other, more nefarious, reasons. It is a mean spirited attack on a vulnerable and politically weak segment of society. For that reason, I oppose them.
Yet the many of the same people are continually seeking to hand out ever more financial bene's to the wealthy based on the most rose colored stereotypes about the virtues of the "job creators."